U.S. patent application number 17/244407 was filed with the patent office on 2021-11-04 for coupling between crankshaft and orbiting scroll plate.
This patent application is currently assigned to Emerson Climate Technologies GmbH. The applicant listed for this patent is Emerson Climate Technologies GmbH. Invention is credited to Linus DELLWEG, Laurence GROSJEAN, Jes s ngel NOHALES HERRAIZ, Xiaogeng SU.
Application Number | 20210340983 17/244407 |
Document ID | / |
Family ID | 1000005596990 |
Filed Date | 2021-11-04 |
United States Patent
Application |
20210340983 |
Kind Code |
A1 |
SU; Xiaogeng ; et
al. |
November 4, 2021 |
Coupling Between Crankshaft And Orbiting Scroll Plate
Abstract
A system for use in a scroll compressor is described. The system
comprises a crankshaft with a first end portion, wherein the
crankshaft defines an axis of rotation, and slider block having a
recess, wherein the first end portion of the crankshaft and the
recess in the slider block are configured for connecting the slider
block to the first end portion. The first end portion of the
crankshaft comprises a first flat contact surface portion and the
recess of the slider block comprises a second flat contact surface
portion, the first and second contact surface portions facing each
other when the first end portion is connected to the slider block.
The system is characterized in that at least one of the flat
contact surface portions comprises a slit beneath the at least one
flat contact surface portion. Further, a corresponding slider block
and a corresponding crankshaft are described.
Inventors: |
SU; Xiaogeng; (Mechelen,
BE) ; NOHALES HERRAIZ; Jes s ngel; (Aachen, DE)
; DELLWEG; Linus; (US) ; GROSJEAN; Laurence;
(US) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Emerson Climate Technologies GmbH |
Berlin |
|
DE |
|
|
Assignee: |
Emerson Climate Technologies
GmbH
Berlin
DE
|
Family ID: |
1000005596990 |
Appl. No.: |
17/244407 |
Filed: |
April 29, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04C 29/0057 20130101;
F04C 18/0215 20130101 |
International
Class: |
F04C 29/00 20060101
F04C029/00; F04C 18/02 20060101 F04C018/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 30, 2020 |
EP |
20172342.6 |
Claims
1. A system for use in a scroll compressor, the system comprising:
a crankshaft with a first end portion, wherein the crankshaft
defines an axis of rotation; a slider block having a recess,
wherein the first end portion of the crankshaft and the recess in
the slider block are configured for connecting the slider block to
the first end portion; wherein the first end portion of the
crankshaft comprises a first flat contact surface portion and the
recess of the slider block comprises a second flat contact surface
portion, wherein the first and second contact surface portions face
each other when the first end portion of the crankshaft is
connected to the slider block, characterized in that at least one
of the flat contact surface portions comprises a slit beneath the
at least one flat contact surface portion.
2. The system according to claim 1, wherein the flat contact
surface portions are defined by a portion of the surface being flat
in a plane of a cross-section oriented perpendicular to the axis of
rotation defined by the crankshaft.
3. The system according to claim 2, wherein at least one of the
flat contact surface portions is curved in a direction parallel to
the axis of rotation defined by the crankshaft.
4. The system according to claim 3, wherein the at least one flat
contact surface portion, which is curved, has a convex surface
portion.
5. The system according to claim 1, wherein the slit is oriented
perpendicular to the axis of rotation defined by the
crankshaft.
6. The system according to claim 1, wherein the slit is oriented
parallel to the axis of rotation defined by the crankshaft.
7. The system according to claim 1, wherein the outer surface of
the slider block is a cylindrical shell surface.
8. A crankshaft for use in a scroll compressor, the crankshaft
comprising: a body, which defines an axis of rotation; and a first
end portion, wherein the crankshaft is configured for applying
force from a motor to a slider block, which is located in a recess
of a scroll plate of the compressor, characterized in that the
first end portion comprises a flat contact surface portion and a
slit beneath the flat contact surface portion.
9. The crankshaft according to claim 8, wherein the slit is
oriented perpendicular to the axis of rotation.
10. The crankshaft according to claim 8, wherein the slit is
oriented parallel to the axis of rotation.
11. The crankshaft according to claim 8, wherein the first end
portion comprises a protruding element, which extends
longitudinally to the axis of rotation from the first end portion
of the crankshaft, and an insert, which is attached to the first
portion, and wherein the slit is formed between the first end
portion and the insert.
12. The crankshaft according to claim 11, wherein at least the
protruding element or the insert comprises a recess for forming the
slit, when the insert is attached to the protruding element.
13. A slider block for use in a scroll compressor, the slider block
comprising: a body, which defines an axis of rotation; and a
recess, wherein the recess is configured for being connected to a
first end portion of a crankshaft; characterized in that the slider
block comprises a flat contact surface portion and a slit beneath
the flat contact surface portion.
14. The slider block according to claim 13, wherein the slit is
oriented perpendicular to the axis of rotation.
15. The slider block according to claim 13, wherein the slit is
oriented parallel to the axis of rotation.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to European Patent
Application No. 20171292.4 filed on Apr. 24, 2020. The entire
disclosure of which is incorporated herein by reference.
FIELD
[0002] The current application relates to a crankshaft and slider
block for use in a compressor, in particular a scroll compressor,
wherein such compressor could be used, for example, in
refrigeration systems.
BACKGROUND
[0003] A compressor is an apparatus, which reduces the volume of a
fluid by increasing the pressure of the fluid. In most common
applications, the fluid is a gas.
[0004] The compressors are used, for example, in refrigeration
systems. In a common refrigeration system, a refrigerant is
circulated through a refrigeration cycle. Upon circulation, the
refrigerant undergoes changes in thermodynamic properties in
different parts of the refrigeration system and transports heat
from one part of the refrigeration system to another part of the
refrigeration system. The refrigerant is a fluid, i.e. a liquid or
a vapour or gas. Examples of refrigerants may be artificial
refrigerants like fluorocarbons. However, in recent applications,
the use of carbon dioxide, CO.sub.2, which is a non-artificial
refrigerant, has become more and more important, because it is
non-hazardous to the environment.
[0005] In the compressor, a motor drives the compression process.
Usually, electric motors are used. The motor provides a force,
which is provided to a means for compressing, in which the fluid is
compressed. In a scroll compressor, the means for compressing is
formed by scroll plates. The force, which is provided by the motor,
is applied to the means for compressing by ease of a
crankshaft.
[0006] In case of a scroll compressor, the scroll compressor
comprises a stationary scroll plate and an orbiting scroll plate.
The force provided by the motor is applied to the orbiting scroll
plate. In order to achieve this, one portion of the crankshaft is
coupled to the motor and another portion, preferably an end
portion, is coupled to the orbiting scroll plate. For example, the
orbiting scroll plate may comprise a recess, in which a slider
block is located. The slider block is configured to receive a
portion of the crankshaft. For example, the crankshaft may comprise
an end portion and the slider block may comprise a recess, wherein
the end portion of the crankshaft fits at least partially into the
recess of the slider block. The end portion of the crankshaft may
be a protruding element, such as a pin.
[0007] During operation, the force applied by the motor causes a
motion of the crankshaft. The motion may be a rotational motion of
the crankshaft around an axis of rotation. The axis of rotation may
be a longitudinal axis, which is defined by the crankshaft. For
example, in case of a cylindrical crankshaft, the axis of rotation
may be the cylinder axis of the cylindrical crankshaft.
[0008] The motion of the crankshaft is transferred to the orbiting
scroll plate, for example by ease of the slider block. The
crankshaft is form-fittingly coupled to the slider block. In an
example, the crankshaft may comprise a first end portion, such as a
pin, which is in form-fitting contact to the slider block, for
example by at least partially extending into a recess of the slider
block. The first end portion may comprise a first flat contact
surface portion and the recess may comprise a corresponding second
flat contact surface portion. When the first end portion is coupled
to the recess, the first and second flat contact surface portions
may engage each other and form contacting surfaces. A flat contact
surface portion in the sense of the current invention refers to a
surface portion, which is flat when looked at in a plane of a
cross-section oriented perpendicular to the axis of rotation
defined by the crankshaft. In a particular example, the first end
portion may have a substantially circular cross-section, wherein a
portion of the circular cross-section may be flattened, thereby,
forming a cross-section in the form of a "D". In other examples,
the cross-section may have other forms, for example the form of a
rectangle.
[0009] When the crankshaft performs a rotational motion, the motion
is transferred to the slider block. Since the crankshaft performs a
rotational motion around the first axis of rotation, the slider
block also performs a rotational motion. Preferably, the slider
block performs a combination of an orbiting motion and a rotational
motion, for example when a center point of the slider block in a
plane perpendicular to the axis of rotation has an offset relative
to the axis of rotation when the slider block is assembled onto the
first end portion of the crankshaft. This may be achieved when a
center point of the first end portion of the crankshaft has an
offset relative to the axis of rotation or when the slider block
has a bore, which is offset to a symmetry axis of the slider block,
wherein the symmetry axis of the slider block is parallel to the
axis of rotation of the crankshaft in an assembled state.
[0010] The slider block may be located in a recess in the orbiting
scroll plate. In said recess, the slider block may rotate freely.
This may be achieved by a cylindrical shell surface of the slider
block. However, the orbiting motion caused by the offset is
transferred from the slider block to the orbiting scroll plate and
causes an orbiting motion of the scroll plate relatively to the
stationary scroll plate.
[0011] In a refrigeration system, the refrigerant is compressed to
a high pressure. The moving components within the compressor, for
example the motor, the crankshaft, and the slider block, move and
work against the high pressure and are therefore subject to
substantial wear. This is an issue, particularly for CO.sub.2
refrigeration systems, since the pressure in CO.sub.2 refrigeration
systems is higher than for artificial refrigerants and therefore
the wear between the crankshaft and the slider block is increased
and can cause failure of the compressor. The wear is in particular
increased at the contacting surfaces between the crankshaft and the
slider block, for example between the first end portion of the
crankshaft and the slider block, in particular the contacting
surfaces formed between them.
[0012] Hence, there is a need in the art for improving the coupling
between the crankshaft and the orbiting scroll plate in a
compressor.
[0013] The above-mentioned need is fulfilled by the crankshaft
and/or slider block configuration according to the invention. The
above-mentioned need is also fulfilled by a system comprising a
crankshaft and a slider block according to the current
invention.
[0014] A system according to the invention is configured for use in
a scroll compressor and comprises a crankshaft and slider
block.
[0015] The crankshaft defines an axis of rotation and comprises a
first end portion. The first end portion may comprise a pin, which
extends from the first end portion and is configured for being
coupled to the slider block. The axis of rotation may be a
longitudinal axis, defined by a body of the crankshaft.
[0016] The slider block comprises a recess. The person skilled in
the art will appreciate that the recess may also be a bore or a
continuous hole. The slider block may have a cylindrical shell
surface.
[0017] The crankshaft may be configured for applying force from a
motor of the compressor to the slider block and thereby to the
orbiting scroll plate of the compressor. This is achieved by the
first end portion of the crankshaft being configured for being
placed at least partially in the recess of the slider block.
Thereby, the first end portion and the recess may form a form-fit
connection for transferring a force provided by the motor from the
crankshaft to the slider block and the orbiting scroll plate.
[0018] The first end portion of the crankshaft comprises a first
flat contact surface portion and the recess of the slider block
comprises a second flat contact surface portion. The first and
second contact surface portions face each other when the first end
portion is placed at least partially in the recess of the slider
block. Thereby, the first and second flat contact surface portions
form contacting surfaces. A flat contact surface portion in the
sense of the current invention refers to a surface portion, which
is flat when looked at in a plane of a cross-section oriented
perpendicular to the axis of rotation defined by the crankshaft. In
a particular example, the first end portion may have a
substantially circular cross-section, wherein a portion of the
circular cross-section may be flattened, thereby, forming a
cross-section in the form of a "D". In another example, the first
end portion may have more than one flat contact surface portions
and may for example have a cross-section in the shape of a
rectangle. The person skilled in the art will understand, that the
flat contact surface portion does not need to be entirely flat.
Instead, it would also be possible that the flat contact surface
portion is slightly curved or has a structure. As used throughout
the description, a surface portion being flat means that the
surface portion is able to engage with a corresponding contact
surface portion of the other component, i.e. the slider block or
the crankshaft.
SUMMARY
[0019] According to the current invention, at least one of the
first and second flat contact surface portions comprises a slit
beneath the at least one flat contact surface portion. The slit
reduces the stiffness of the flat contact surface portion. This
allows for improving the contact between the first flat contact
surface portion and the second flat contact surface portion of the
respective other component.
[0020] In some preferred embodiments, at least one of the two flat
contact surface portions may be curved in a direction parallel to
the axis of rotation defined by the crankshaft. The curved surface
portion, which is formed this way, may be a convex surface
portion.
[0021] The slit causes a reduced stiffness of the material in the
surface area of the respective flat contact surface portion.
Because of the reduced stiffness, the flat contact surface portion
can at least partially adjust its shape to the flat contact surface
portion of the other component. Preferably, the flat contact
surface portion of the other component is slightly curved in a
direction perpendicular to the direction in which the contact
surface portion looks flat. For example, the flat contact surface
portion of the other component may be flat in a cross-section
perpendicular to the axis of rotation of the crankshaft and may be
curved in a direction parallel to the axis of rotation defined by
the crankshaft. This increase reduces the contact stress and the
wear and improves the durability and lifetime of the coupling
between the crankshaft and the orbiting scroll plate via the slider
block.
[0022] In preferred embodiments, the slit is oriented perpendicular
to the axis of rotation defined by the crankshaft. More preferably,
one of the two components has a convex surface portion, which is
curved along a direction parallel to the axis of rotation defined
by the crankshaft as described before. Having the slit
perpendicular to the axis of rotation of the crankshaft and the
convex surface portion curved along a direction perpendicular to
the direction of the slit improves the adjustment of the flat
contact surface portion to the convex surface portion.
[0023] Similarly, in some other preferred embodiments, the slit is
oriented parallel to the axis of rotation defined by the
crankshaft. More preferably, the curved surface portion is curved
along a direction perpendicular to the axis of rotation defined by
the crankshaft. Having the slit parallel to the axis of rotation
defined by the crankshaft and the curved surface portion curved
along a direction perpendicular to the direction of the slit
improves the adjustment of the flat contact surface portion to the
curved surface portion.
[0024] In any of these embodiments, the slider block preferably has
a cylindrical shell surface.
[0025] The above-mentioned need is also overcome by a crankshaft
according to the current invention. A crankshaft according to the
current invention is configured for use in a scroll compressor. The
crankshaft comprises a body, which defines an axis of rotation, and
a first end portion. The crankshaft is configured for applying
force from a motor to a slider block, which is located in a recess
of a scroll plate of the compressor.
[0026] According to the current invention, the first end portion
comprises a flat contact surface portion and a slit beneath the
flat contact surface portion. The slit reduces the stiffness of the
flat surfaces. This allows for improving the contact between the
flat contact surface portion of the flat contact surface portion
and the slider block. As has been described before, a flat contact
surface portion in the sense of the current invention refers to a
surface portion, which is flat when looked at in a plane of a
cross-section oriented perpendicular to the axis of rotation
defined by the crankshaft. Thereby, the cross-section of the first
end portion of the crankshaft may have a "D" shape.
[0027] In some preferred embodiments, the slit is oriented
perpendicular to the axis of rotation defined by the body of the
crankshaft. This is in particular beneficial if the first end
portion of the crankshaft shall be placed in a recess of a slider
block, when the recess comprises a curved surface portion and the
curved surface is curved along a direction parallel to the axis of
rotation.
[0028] In some preferred embodiments, the slit is oriented parallel
to the axis of rotation defined by the body of the crankshaft. This
is in particular beneficial if the first end portion of the
crankshaft shall be placed in a recess of a slider block, when the
recess comprises a curved surface portion and the curved surface is
curved along a direction perpendicular to the axis of rotation.
[0029] In some preferred embodiments, the first end portion
comprises a protruding element, which extends longitudinally to the
axis of rotation from the first end portion of the crankshaft, and
an insert, which is attached to the protruding element, and wherein
the slit is formed between the protruding element and the insert.
This may improve the manufacturing of the crankshaft, because the
insert can be added to a conventional crankshaft. At least one of
the protruding element and the insert may comprise a recess for
forming the slit, when the insert is attached to the protruding
element.
[0030] The above-mentioned need is also overcome by a slider block
according to the current invention. A slider block according to the
current invention is configured for use in a scroll compressor and
comprises a body, which defines an axis of rotation, and a recess.
The body may be a cylindrical body. The cylindrical body may have a
top surface and a bottom surface, as well as a cylindrical outer
surface. The recess may be located at the top surface or the bottom
surface. The recess may extend at least partially into the body of
the slider block. In some embodiments, the recess may be a bore or
a continuous hole, which extends from the bottom surface to the top
surface entirely.
[0031] According to the current invention, the slider block
comprises a flat contact surface portion and a slit beneath the
flat contact surface portion. The flat contact surface portion is
an inner surface portion of the recess. The slit reduces the
stiffness of the flat surfaces. This allows for improving the
contact between the flat contact surface portion of the pin and the
slider block. Similar to what has been described before, a flat
contact surface portion in the sense of the current invention
refers to a surface portion, which is flat when looked at in a
plane of a cross-section oriented perpendicular to an axis of
rotation defined by the crankshaft, or in case of the slider block
the axis of rotation defined by the body of the slider block.
Thereby, the recess of the slider block may have a "D" shape.
[0032] In some preferred embodiments, the slit is oriented
perpendicular to the axis of rotation defined by the body of the
slider block. This is in particular beneficial if the slider block
is used in combination with a first end portion of a crankshaft,
when the first end portion comprises a curved surface portion and
the curved surface is curved along a direction parallel to the
cylinder axis of the slider block.
[0033] In some preferred embodiments, the slit is oriented parallel
to the axis of rotation defined by the body of the slider block.
This is in particular beneficial if the slider block is used in
combination with a first end portion of a crankshaft, when the
first end portion comprises a curved surface portion and the curved
surface is curved along a direction perpendicular to the cylinder
axis of the slider block.
[0034] The person skilled in the art will appreciate that any
configuration, which comprises a slit in the first end portion of
the crankshaft as well as a slit in the slider block will not
deviate from the current application, but is also encompassed.
Therefore, further slits are possible. For example, it may be
possible that a flat contact surface portion of a first end portion
of a crankshaft comprises a slit, while also a flat contact surface
portion of a slider block comprises a slit.
[0035] The following description and the annexed drawings set forth
in detail certain illustrative aspects of the system and
apparatuses described above. These aspects are indicative, however,
of but a few of the various ways in which the principles of various
embodiments can be employed and the described embodiments are
intended to include all such aspects and their equivalent. In
particular it needs to be highlighted that--although the following
drawings only show embodiment examples of scroll compressors--the
invention may be applied to any type of compressor.
DRAWINGS
[0036] In the drawings, like reference characters generally refer
to the same parts throughout the different drawings. The drawings
are not necessarily to scale, emphasis instead generally being
placed upon illustrating the principles of the invention.
[0037] In the following description, various embodiments of the
invention are described with reference to the following drawings,
in which:
[0038] FIG. 1 shows a cross-sectional view of an embodiment of a
scroll compressor according to the current invention.
[0039] FIG. 2a, 2b show detail images of a crankshaft and slider
block according to the current invention (a) in an assembled state
with an orbiting scroll plate and (b) in an exploded view.
[0040] FIG. 3a, 3b show detail images of (a) a first end portion of
a crankshaft and a slider block according to the state of the art
and (b) the engagement of the flat contact surface portion of the
first end portion of the crankshaft and a flat contact surface
portion of the slider block, which is curved in a direction
perpendicular to the axis of rotation defined by the
crankshaft.
[0041] FIG. 4a, 4b show detail images of (a) a first end portion of
a crankshaft and a slider block according to the current invention
and (b) the engagement of the flat contact surface portion of the
first end portion of the crankshaft and a flat contact surface
portion of the slider block, which is curved in a direction
perpendicular to the axis of rotation defined by the
crankshaft.
[0042] FIGS. 5a to 5f show embodiment examples of first end
portions of a crankshaft according to the current invention,
wherein the first end portion comprises a flat contact surface
portion and a slit, which is oriented perpendicular to the axis of
rotation defined by the body of the crankshaft.
[0043] FIG. 6 shows an embodiment example of a first end portion of
a crankshaft according to the current invention, wherein the first
end portion comprises a flat contact surface portion and a slit,
which is oriented parallel to the axis of rotation defined by the
body of the crankshaft.
[0044] FIG. 7a, 7b show embodiment examples of slider blocks
according to the current invention, wherein the slider block
comprises a flat contact surface portion and a slit, which is (a)
perpendicular to the axis of rotation defined by a crankshaft and
(b) longitudinal to said axis.
DETAILED DESCRIPTION
[0045] The following detailed description refers to the
accompanying drawings that show, by way of illustration, specific
details and embodiments in which the invention may be
practiced.
[0046] The word "exemplary" is used herein to mean "serving as an
example, instance, or illustration". Any embodiment or design
described herein as "exemplary" is not necessarily to be construed
as preferred or advantageous over other embodiments or designs.
[0047] FIG. 1 shows a cross-sectional view of an embodiment of a
scroll compressor according to the current invention. The
compressor 100 comprises a case 190 and a suction port 160 for
receiving refrigerant. The compressor 100 compresses the
refrigerant in a compression chamber. Since compressor 100 is a
scroll compressor, the compression chamber is formed by a scroll
set comprising a stationary scroll plate 155 and an orbiting scroll
plate 150. After compression, the refrigerant will be discharged
from a discharge port 170. Moving parts inside the compressor 100
are lubricated by a lubricant, which is provided by a lubricant
sump 180.
[0048] The compressor 100 comprises a motor 105. The motor 105 is
used to drive the compressor by agitating the compression chamber,
in particular by causing an orbiting motion of the orbiting scroll
plate 150. In order to achieve this, the compressor comprises a
crankshaft 110. A portion of the crankshaft 110 is connected to the
motor 105.
[0049] During operation, the motor 105 causes a rotational motion
of the crankshaft 110 around an axis of rotation. The rotational
motion is transferred from the crankshaft 110 to an orbiting motion
of the orbiting scroll plate 150. The crankshaft 110 comprises a
first end portion with a pin 115, which extends longitudinally to
the axis of rotation from an end portion of the crankshaft 110. A
center of the pin 115 may be offset to the axis of rotation.
[0050] The pin 115 engages a slider block 130. The slider block 130
has a cylindrical body and comprises a recess in form of a bore,
wherein a center of the bore is offset to the axis of rotation. The
pin 115 at least partially extends into the bore. The slider block
130 rotates around the axis of rotation of the crankshaft and
because of the offset, the slider block 130 also orbits around the
axis of rotation at the same time. The slider block 130 is located
in a recess of the orbiting scroll plate 150. Said recess comprises
boundaries. The boundaries form an approximately cylindrical
recess, which has a diameter slightly larger than the diameter of
the cylindrical slider block. Because of the cylindrical body, the
slider block 130 can freely rotate inside the recess of the
orbiting scroll plate 150, without locking with the boundaries and
therefore without transferring any rotational motion to the
orbiting scroll plate 150. However, the orbiting motion of the
slider block 130 causes a force against the boundaries of the
recess and thereby cause an orbiting motion of the orbiting scroll
plate 150, but without any rotation.
[0051] The pin 115, which engages the slider block 130, comprises a
slit 125, which reduces the stiffness of a surface portion of the
pin 115, wherein the surface portion is in contact with the slider
block 130. This will be shown in more detail further below with
reference to FIGS. 3 and 4.
[0052] FIGS. 2a and 2b show detail images of a crankshaft and
slider block according to the current invention (a) in an assembled
state with an orbiting scroll plate and (b) in an exploded
view.
[0053] FIG. 2a shows the pin 115 of the first end portion of the
crankshaft 110, the slider block 130 and the orbiting scroll plate
150 in more detail in an assembled state. In a recess on the
backside of the orbiting scroll plate 150, the slider block 130 is
located and the pin 115 of the first end portion of the crankshaft
110 is located in a recess or opening 135 of the slider block 130.
When the crankshaft 110 rotates, the pin 115 rotates as well and
the motion is transferred to the slider block 130. Since the slider
block 130 usually has a cylindrical outer surface, as can be seen
in the exploded view in FIG. 2b, the slider block 130 can rotate
within the recess of the orbiting scroll plate 150, without
transferring the rotational motion to the orbiting scroll plate
150. Since the center of the bore of the slider block 130 is offset
to the rotational axis of the crankshaft 110 when the slider block
130 and the pin 115 are assembled, the slider block 130 also
performs an orbiting motion around the rotation axis, which is
transferred to the orbiting scroll plate.
[0054] FIGS. 3a and 3b are detail images of (a) a first end portion
of a crankshaft and a slider block according to the current
invention and (b) the engagement of the flat contact surface
portions of the first end portion of the crankshaft and a flat
contact surface portion of the slider block, which is curved in a
direction perpendicular to the axis of rotation defined by the
crankshaft.
[0055] In FIGS. 3a, a crankshaft 210 and a slider block 230
according to the state of art are shown. The crankshaft 210
comprises a first end portion with a pin 215 with a flat contact
surface portion 215a. Also, the crankshaft 210 comprises a
lubricant supply passage 220, which is used for providing lubricant
from a lubricant sump to the upper crankshaft portion, the slider
block 230, and the orbiting scroll plate. The lubricant supply
passage 220 is an optional element, but it improves the lubricant
supply and reduces the wear between the moving elements.
[0056] The slider block 230 comprises a recess in form of a bore
and a flat contact surface portion 230a, which is curved in a
direction perpendicular to the axis of rotation defined by the
crankshaft, at an inner portion of the bore. As has been described
earlier, the surface portion 230a is still flat in the sense that
the surface portion is flat when viewed in a cross-section
perpendicular to the axis of rotation defined by the crankshaft
210. When the pin 215 is placed at least partially within the bore
of the slider block 230, the flat contact surface portion 215a of
the pin 215 and the surface portion 230a of the slider block 230
engage each other and form contacting surfaces. Preferably, the
surface 230a may be curved in a convex manner as shown in FIG.
3a.
[0057] When the crankshaft 210 is rotating, the pin 215 is pushed
against the surface portion 230a of the slider block 230 as shown
in FIG. 3b. Thereby, curving the surface 230a is used to compensate
manufacturing imperfections and create a fitting contact with the
flat contact surface portion 215a of the pin 215.
[0058] However, curving the surface portion 230a reduces the
contact area between the contacting surfaces, as can be seen in
FIG. 3b, which shows a detail image of the flat contact surface
portion 215a and the surface portion 230a of slider block 230. This
small contact area between the contacting surfaces increases the
wear between the crankshaft 210 and the slider block 230, thereby
reducing the durability and the lifetime of the compressor.
[0059] FIGS. 4a and 4b show detail images of (a) a first end
portion of a crankshaft and a slider block according to the current
invention and (b) the engagement of the flat contact surface
portion of the first end portion of the crankshaft and a flat
contact surface portion of the slider block, which is curved in a
direction perpendicular to the axis of rotation defined by the
crankshaft.
[0060] In FIG. 4a, crankshaft 310 comprises a first end portion
with a pin 315 with a flat contact surface portion 315a. Further,
the crankshaft comprises a lubricant supply passage 320, which is
again optional. According to the current invention, the pin 315
comprises a slit 325 beneath the flat contact surface portion 315a.
The slit 325 reduces the stiffness of the material locally, in
particular the stiffness of the material of the crankshaft pin
between the flat contact surface portion 315a and the slit 325,
because the material can be bend into the slit 325 upon pressure
against the flat contact surface portion 315a.
[0061] FIG. 4b shows a detail image of the contact between the flat
contact surface portion 315a and the surface portion 330a of the
slider block 330, which is curved in a direction perpendicular to
the axis of rotation defined by the crankshaft. Upon pressure, the
flat contact surface portion 315a of the pin 315 is pushed against
the surface portion 330a of the slider block 330. The pressure at
the contacting area and the reduced stiffness of the material
between the flat contact surface portion 315a and the slit 325
cause a bending of the flat contact surface portion 315a into the
slit 325. This increases the contacting area between the bended
flat contact surface portion 315a and the surface portion 330a of
the slider block 330a. An increased contact area reduces the wear
and increases the durability and lifetime of the compressor.
[0062] FIGS. 5a to 5f show embodiment examples of first end
portions of a crankshaft according to the current invention,
wherein the first end portion comprises a slit, which is oriented
perpendicular to an axis of rotation defined by the body of the
crankshaft.
[0063] In the embodiment example depicted in FIG. 5a, a crankshaft
410 with a first end portion and a pin 415 is shown. The crankshaft
410 comprises an optional lubricant supply passage 420. The pin 415
comprises a flat contact surface portion 415a. A slit 425 is
created by cutting a recess into the pin 415 from the top of the
crankshaft pin 415. Afterwards, the recess is closed at the top
with an insert 430.
[0064] In the embodiment example depicted in FIG. 5b, a crankshaft
510 with a pin 515 is shown. The crankshaft 510 comprises an
optional lubricant supply passage 520. The pin 515 comprises a flat
contact surface portion 515a. A slit 525 is created by forming a
recess in the pin at the location of the slit 525 and placing an
insert 530 on top of the slit 525. The insert 530 comprises the
flat contact surface portion 515a.
[0065] In the embodiment example depicted in FIG. 5c, a crankshaft
610 with a first end portion and a pin 615 is shown. The crankshaft
610 comprises an optional lubricant supply passage 620. The pin 615
comprises a flat contact surface portion 615a. A slit 625 is
created by placing an insert 630 on a side of the pin 615, wherein
the insert comprises a recess on its backside, which forms the slit
625 and a flat contact surface portion 615a on its frontside.
[0066] The person skilled in the art will appreciate that the slit
may also be formed by a recess in the pin of the crankshaft in
combination with a recess on the backside of an insert, which is
placed above the recess of the pin.
[0067] In the embodiment example depicted in FIG. 5d, a crankshaft
710 with a first end portion and a pin 715 is shown on the left
hand side in a perspective view and on the right hand side in a top
view. The crankshaft 710 comprises an optional lubricant supply
passage 720. The pin 715 comprises a flat contact surface portion
715a. The slit portion 725 is formed by two slits 725a, 725b, which
do not extend through the entire thickness of the pin. Instead, a
bar 725c separate the two slits 725a, 725b. Such a configuration
avoids that the slit reduces the stiffness too much and provides
more stability than, for example, the embodiment depicted in FIG.
5a.
[0068] The embodiment example depicted in FIG. 5e is similar to the
embodiment example depicted in FIG. 5d, however, the bar does not
separate the two slits over the entire height of the slit, wherein
the height refers to the extend of the slit in the direction
parallel to the rotation axis of the crankshaft. For example, as is
depicted in FIG. 5d, the bar separates the slits in the areas 825a
and 825c, but not in area 825b. Such a configuration may be used in
a situation where a bar would create too much stiffness, but a slit
extending through the entire thickness of the pin would create too
much instability.
[0069] In the embodiment example depicted in FIG. 5f, a crankshaft
910 with a first end portion and a pin 915 is shown on the left
hand side in a perspective view and on the right hand side in a top
view. The crankshaft 910 comprises an optional lubricant supply
passage 920. The pin 915 comprises a flat contact surface portion
915a. The slit portion 925 is formed by two slits 925a, 925b, which
do not extend through the entire thickness of the pin. In contrast
to the embodiment example depicted in FIG. 5d, the two slits 925a,
925b are offset from one another.
[0070] In the embodiment examples of FIGS. 5a to 5f, the slits 425,
525, 625, 725, 825, 925 are oriented perpendicular to the axis of
rotation of the respective crankshaft.
[0071] FIG. 6 shows an embodiment example of a first end portion of
a crankshaft according to the current invention, wherein the first
end portion comprises a slit, which is oriented parallel to an axis
of rotation defined by the body of the crankshaft.
[0072] In the embodiment example depicted in FIG. 6, a crankshaft
1010 with a first end portion and a pin 1015 is shown. The
crankshaft 1010 comprises an optional lubricant supply passage
1020. The pin 1015 comprises a flat contact surface portion 1015a.
A slit 1025 is created by cutting the slit into the pin from the
top of the pin 1015.
[0073] In the embodiment example of FIG. 6, the slit 1025 extends
parallel to the axis of rotation of the crankshaft 1010.
[0074] FIGS. 7a and 7b show embodiment examples of slider blocks
according to the current invention, wherein the slider block
comprises a slit, which is (a) perpendicular to the axis of
rotation defined by a crankshaft and (b) longitudinal to said
axis.
[0075] FIG. 7a shows an embodiment example of a slider block 1130.
The slider block 1130 has a cylindrical body with a recess in form
of a bore 1135. The bore 1135 extends from the top of the
cylindrical body to the bottom. In some examples, the bore does not
need to extend along the entire height of the cylindrical body. The
bore 1130 comprises a flat contact surface portion 1135a for
locking with a corresponding surface of a crankshaft pin, when the
pin is placed at least partially inside the bore 1135. Beneath the
flat contact surface portion 1135a, the slider block 1130 comprises
a slit 1140. The slit 1140 is oriented perpendicular to the
cylinder axis of the cylindrical body of the slider block 1130.
[0076] FIG. 7b shows an embodiment example of a slider block 1230.
The slider block 1230 has a cylindrical body with a bore 1235. The
bore 1235 extends from the top of the cylindrical body to the
bottom. In some examples, the bore does not need to extend along
the entire height of the cylindrical body. The bore 1230 comprises
a flat contact surface portion 1235a for locking with a
corresponding surface of a crankshaft pin, when the pin is placed
at least partially inside the bore 1235. Beneath the flat contact
surface portion 1235a, the slider block 1230 comprises a slit 1240.
The slit 1240 is oriented parallel to the cylinder axis of the
cylindrical body of the slider block 1230.
[0077] What has been described above includes examples of one or
more embodiments. It is, of course, not possible to describe every
conceivable combination of components or methodologies for purposes
of describing the aforementioned embodiments, but one of ordinary
skill in the art may recognize that many further combinations and
permutations of various embodiments are possible. Accordingly, the
described embodiments are intended to embrace all such alterations,
modifications and variations that fall within the scope of the
appended claims.
* * * * *